1. Field of the Invention
The present disclosure relates to particle size-controlled, chromium oxide particles or composite particles of iron oxide-chromium alloy and chromium oxide; a preparation method thereof; and use thereof.
2. Description of the Related Art
Chromium oxide particles have very high thermal stability and sintering between the particles does not easily occur, and therefore, chromium oxide particles can be very usefully applied to a catalyst or support for high-temperature reactions. However, a synthetic method thereof complex or requires use of environmentally hazardous reagents, and it not easy to obtain small uniform products at a nano level.
Iron oxide and chromium oxide materials can be used as a gas sensor, an electrode material, a catalyst, etc. With regard to catalytic reactions, iron oxide and chromium oxide materials may be applied to the following representative water gas shift (WGS) or reverse water gas shift (RWGS) reaction.CO2+H2CO+H2O
In particular, the reverse water gas shift reaction of producing water and carbon monoxide from carbon dioxide and hydrogen gas is a weak endothermic reaction, and favored at high temperatures. However, nanoparticles used as a catalyst may have lower thermal stability and their sintering may easily occur as their size smaller. To solve this sintering problem, a metal oxide material such as porous silica can be used as a support. However, silica has a disadvantage of being vulnerable to steam, and thus silica is not suitable for use as a support in the high-temperature water gas shift reaction.
Accordingly, chromium oxide nanoparticles being stable against steam or high-temperature reactions have advantages of being suitable for use as a catalyst or support in the high-temperature reverse water gas shift reaction as well as of being used an excellent catalyst in other high-temperature catalytic reactions.